STL 容器文档
@author 鲁伟林
之前常用的语言是: C++。现在使用的是Java，所以抽空整理下C++集合的使用方法。
gitHub地址：https://github.com/thinkingfioa/Notes/blob/master/TechFiles/STL_Usage.md
主要通过Demo下列容器用法 + 遍历算法:
1. vector[push_back, pop_back, insert, erase, swap]
2. set[insert, erase, swap, find, count]
3. stack[top, push, pop, swap]
4. queue[push, pop, swap, back, front]
5. map[insert, erase, swap]
6. deque[front, back, push_back, push_front, pop_back, pop_front, insert, erase, swap]
7. Algorithm[find, copy, swap, count, replace, fill, reverse, merge, min, max]
1. vector
1.1 push_back()函数
代码:
vector myVector;
myVector.push_back(100);
1.2 pop_back()函数
代码:
vector myVector;
myVector.push_back(100);
myVector.push_back(200);
myVector.push_back(300);
//执行前: 100, 200, 300
myVector.pop_back();
//执行后: 100, 200
1.3 insert()函数
代码:
#include
#include
int main ()
{
std::vector myvector (3,100);
std::vector::iterator it;
//执行前: 100, 100, 100
it = myvector.begin();
it = myvector.insert ( it , 200 );
//执行后: 200, 100, 100, 100
//执行前: 200, 100, 100, 100
myvector.insert (it,2,300);
//执行后: 300, 300, 200, 100, 100, 100
// "it" no longer valid, get a new one:
it = myvector.begin();
//执行前: 300, 300, 200, 100, 100, 100
std::vector anothervector (2,400);
myvector.insert (it+2,anothervector.begin(),anothervector.end());
//执行后: 300, 300, 400, 400, 200, 100, 100, 100
int myarray [] = { 501,502,503 };
//执行前: 300, 300, 400, 400, 200, 100, 100, 100
myvector.insert (myvector.begin(), myarray, myarray+3);
//执行后: 501, 502, 503, 300, 300, 400, 400, 200, 100, 100, 100
return 0;
}
1.4 erase()函数
代码:
vector myVector;
for(int i =0; i<10;i++) {
myVector.push_back(i);
}
//执行前: 1, 2, 3, 4, 5, 6, 7, 8, 9
myVector.erase(myVector.begin() +5); // 移除下标为5的数,也就是myVector[5]=6
//执行后: 1, 2, 3, 4, 5, 7, 8, 9
//执行前: 1, 2, 3, 4, 5, 7, 8, 9
myVector.erase(myVector.begin(), myVector.begin() + 3);
//执行后: 4, 5, 7, 8, 9
1.5 swap()函数
代码:
std::vector foo (3,100); // three ints with a value of 100
std::vector bar (5,200); // five ints with a value of 200
//执行前: foo: [100, 100, 100]
// bar: [200, 200, 200, 200, 200]
foo.swap(bar);
//执行后: foo: [200, 200, 200, 200, 200]
// bar: [100, 100, 100]
1.6 遍历
迭代器遍历:
for (it=myvector.begin(); it
2. set
2.1 insert()函数
代码:
std::set myset;
std::set::iterator it;
std::pair::iterator,bool> ret;
// set some initial values:
for (int i=1; i<=5; ++i) myset.insert(i*10);
//执行前: 10, 20, 30, 40, 50
ret = myset.insert(20); // no new element inserted
//执行后: 10, 20, 30, 40, 50
if (ret.second==false) it=ret.first; // "it" now points to element 20
//执行前: 10, 20, 30, 40, 50
myset.insert (it,25); // max efficiency inserting
myset.insert (it,24); // max efficiency inserting
myset.insert (it,26); // no max efficiency inserting
//执行后: 10, 20, 24, 25, 26, 30, 40, 50
//执行前: 10, 20, 24, 25, 26, 30, 40, 50
int myints[]= {5,10,15}; // 10 already in set, not inserted
myset.insert (myints,myints+3);
//执行后: 5, 10, 15, 20, 24, 25, 26, 30, 40, 50
2.2 erase()函数
代码:
std::set myset;
std::set::iterator it;
// insert some values:
for (int i=1; i<10; i++) myset.insert(i*10); // 10 20 30 40 50 60 70 80 90
it = myset.begin();
++it; // "it" points now to 20
// 执行前: 10, 20, 30, 40, 50, 60, 70, 80, 90; //(*it) = 20
myset.erase (it);
//执行后: 10, 30, 40, 50, 60, 70, 80, 90;
//执行前: 10, 30, 40, 50, 60, 70, 80, 90;
myset.erase (40);
//执行后: 10, 30, 50, 60, 70, 80, 90;
it = myset.find (60);
//执行前: 10, 30, 50, 60, 70, 80, 90;
myset.erase (it, myset.end());
//执行后: 10, 30, 50;
2.3 swap()函数
代码:
int myints[]={12,75,10,32,20,25};
std::set first (myints,myints+3); // 10,12,75
std::set second (myints+3,myints+6); // 20,25,32
//执行前: first [10, 12, 75]
// second [20, 25, 32]
first.swap(second);
//执行后: first [20, 25, 32]
// second [10, 12, 75]
2.4 find()函数
代码:
std::set myset;
std::set::iterator it;
// set some initial values:
for (int i=1; i<=5; i++) myset.insert(i*10); // set: 10 20 30 40 50
// 执行前: 10, 20, 30, 40, 50
it=myset.find(20);
myset.erase (it);
// 执行后: 10, 30, 40, 50
2.5 count()函数
代码:
由于set集合不重复，所以count(val)返回的结果只有0或者1.
std::set myset;
// set some initial values:
for (int i=1; i<5; ++i) myset.insert(i*3); // set: 3 6 9 12
//返回结果是: 1
myset.count(3);
//返回结果是: 0
myset.count(5);
2.6 遍历
int myints[] = {75,23,65,42,13};
std::set myset (myints,myints+5); //13, 23, 42, 65, 75
for (std::set::iterator it=myset.begin(); it!=myset.end(); ++it){
std::cout << ' ' << *it;
}
3. stack
3.1 top()函数
代码:
std::stack mystack;
mystack.push(10);
mystack.push(20);
mystack.top() -= 5; //mystack.top() 的值为20
3.2 push()函数
代码:
std::stack mystack;
for (int i=0; i<5; ++i) mystack.push(i);
3.3 pop()函数
3.4 swap()函数
代码:
std::stack foo,bar;
foo.push (10); foo.push(20); foo.push(30);
bar.push (111); bar.push(222);
// 执行前: foo [10, 20, 30]
// bar [111, 222]
foo.swap(bar);
// 执行后: foo [111, 222]
// bar [10, 20, 30]
3.5 遍历
std::cout << "Popping out elements...";
while (!mystack.empty())
{
std::cout << ' ' << mystack.top();
mystack.pop();
}
std::cout << '\n';
4. map
c++ 中的map是默认按照key的排序。所以每次插入都会做调整。
4.1 insert()函数
代码:
std::map mymap;
// first insert function version (single parameter):
mymap.insert ( std::pair('a',100) );
4.2 erase()函数
代码:
std::map mymap;
std::map::iterator it;
// insert some values:
mymap['a']=10;
mymap['b']=20;
mymap['c']=30;
mymap['d']=40;
mymap['e']=50;
mymap['f']=60;
it=mymap.find('b');
//执行前: a->10, b->20, c->30, d->40, e->50, f->60
mymap.erase (it); // erasing by iterator
//执行后: a->10, c->30, d->40, e->50, f->60
//执行前: a->10, c->30, d->40, e->50, f->60
mymap.erase ('c'); // erasing by key
//执行后: a->10, d->40, e->50, f->60
it=mymap.find ('e');
//执行前: a->10, d->40, e->50, f->60
mymap.erase ( it, mymap.end() ); // erasing by range
//执行后: a->10, d->40
4.3 swap()函数
代码:
std::map foo,bar;
foo['x']=100;
foo['y']=200;
bar['a']=11;
bar['b']=22;
bar['c']=33;
// 执行前: foo [x->100, y->200]
// bar [a->11, b->22, c->33]
foo.swap(bar);
// 执行前: foo [a->11, b->22, c->33]
// bar [x->100, y->200]
4.4 遍历
代码:
for (std::map::iterator it=foo.begin(); it!=foo.end(); ++it) {
std::cout << it->first << " => " << it->second << '\n';
}
5. queue
5.1 push()函数
代码:
std::queue myqueue;
myqueue.push (myint);
5.2 pop()函数
5.3 swap()函数
代码:
std::queue foo,bar;
foo.push (10); foo.push(20); foo.push(30);
bar.push (111); bar.push(222);
// 执行前: foo[10, 20, 30]
// bar[111, 222]
foo.swap(bar);
// 执行后: foo[111, 222]
// bar[10, 20, 30]
5.4 back()函数
代码:
myqueue.push(12);
myqueue.push(75); // this is now the back
//执行前: 12, 75
myqueue.back() -= myqueue.front();
//执行后: 12, 63
5.5 front()函数
代码:
myqueue.push(77);
myqueue.push(16);
//执行前: 77, 16
myqueue.front() -= myqueue.back(); // 77-16=61
//执行后: 61, 16
5.6 遍历
代码:
std::cout << "myqueue contains: ";
while (!myqueue.empty())
{
std::cout << ' ' << myqueue.front();
myqueue.pop();
}
6. deque
6.1 front()函数
代码:
std::deque mydeque;
mydeque.push_front(77);
mydeque.push_back(20);
//执行前: 77, 20
mydeque.front() -= mydeque.back();
//执行后: 57, 20
6.2 back()函数
代码:
std::deque mydeque;
mydeque.push_back(10);
while (mydeque.back() != 0)
mydeque.push_back ( mydeque.back() -1 );
6.3 push_back()函数
代码:
std::deque mydeque;
//执行前: []
mydeque.push_back(1);
//执行后: [1]
//执行前: [1]
mydeque.push_back(2);
//执行后: [1,2]
6.4 push_front()函数
代码:
std::deque mydeque (2,100); // two ints with a value of 100
//执行前: 100, 100
mydeque.push_front (200);
//执行后: 200, 100, 100
//执行前: 200, 100, 100
mydeque.push_front (300);
//执行前: 300, 200, 100, 100
6.5 pop_back()函数
代码:
//执行前:
mydeque.push_back (10);
mydeque.push_back (20);
mydeque.push_back (30);
//执行后: 10, 20, 30
//执行前: 10, 20, 30
mydeque.pop_back();
//执行后: 10, 20
6.6 pop_front()函数
代码:
//执行前:
mydeque.push_back (100);
mydeque.push_back (200);
mydeque.push_back (300);
//执行后: 100, 200, 300
//执行前: 100, 200, 300
mydeque.pop_front();
//执行后: 200, 300
6.7 insert()函数
代码:
std::deque mydeque;
// set some initial values:
for (int i=1; i<6; i++) mydeque.push_back(i); // 1 2 3 4 5
std::deque::iterator it = mydeque.begin();
++it;
//执行前: 1, 2, 3, 4, 5
it = mydeque.insert (it,10);
//执行后: 1, 10, 2, 3, 4, 5
// "it" now points to the newly inserted 10
//执行前: 1, 10, 2, 3, 4, 5
mydeque.insert (it,2,20); // 1 20 20 10 2 3 4 5
//执行后: 1, 20, 20, 10, 2, 3, 4, 5
// "it" no longer valid!
it = mydeque.begin()+2;
//执行前: 1, 20, 20, 10, 2, 3, 4, 5
std::vector myvector (2,30);
mydeque.insert (it,myvector.begin(),myvector.end());
//执行后: 1, 20, 30, 30, 20, 10, 2, 3, 4, 5
6.8 erase()函数
代码:
// set some values (from 1 to 10)
for (int i=1; i<=10; i++) mydeque.push_back(i);
// erase the 6th element
//执行前: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
mydeque.erase (mydeque.begin()+5);
//执行后: 1, 2, 3, 4, 5, 7, 8, 9, 10
// erase the first 3 elements:
//执行前: 1, 2, 3, 4, 5, 7, 8, 9, 10
mydeque.erase (mydeque.begin(),mydeque.begin()+3);
//执行后: 4, 5, 7, 8, 9, 10
6.9 swap()函数
代码:
unsigned int i;
std::deque foo (3,100); // three ints with a value of 100
std::deque bar (5,200); // five ints with a value of 200
//执行前: foo [100, 100, 100]
// bar [200, 200, 200, 200, 200]
foo.swap(bar);
//执行后: foo [200, 200, 200, 200, 200]
// bar [100, 100, 100]
6.10 遍历
代码:
for (std::deque::iterator it = mydeque.begin(); it!=mydeque.end(); ++it) {
std::cout << ' ' << *it;
}
while (!mydeque.empty()) {
sum+=mydeque.back();
mydeque.pop_back();
}
7. algorithm
7.1 find()函数
代码:
//数组中查询
int myints[] = { 10, 20, 30, 40 };
int * p;
p = std::find (myints, myints+4, 30);
if (p != myints+4)
//输出: 30
else
std::cout << "Element not found in myints\n";
// vector中查询
std::vector myvector (myints,myints+4);
std::vector::iterator it;
it = find (myvector.begin(), myvector.end(), 30);
if (it != myvector.end())
//输出: 30
else
std::cout << "Element not found in myvector\n";
7.2 copy()函数
代码:
int myints[]={10,20,30,40,50,60,70};
std::vector myvector (7);
//执行前: myvector:
std::copy ( myints, myints+7, myvector.begin() );
//执行前: myvector: 10, 20, 30, 40, 50, 60, 70
7.3 swap()函数
代码:
int x=10, y=20; // x:10 y:20
//执行前: x:10, y:20
std::swap(x,y); // x:20 y:10
//执行后: x:20, y:10
std::vector foo (4,x), bar (6,y); // foo:4x20 bar:6x10
//执行前: foo[20, 20, 20, 20]
// bar[10, 10, 10, 10]
std::swap(foo,bar); // foo:6x10 bar:4x20
//执行前: foo[20, 20, 20, 20]
// bar[10, 10, 10, 10]
7.4 count()函数
代码:
int myints[] = {10,20,30,30,20,10,10,20}; // 8 elements
//记录数组myints中，10的个数
int mycount = std::count (myints, myints+8, 10);
//输出结果 mycount = 3
std::vector myvector (myints, myints+8);
//记录数组myvector中，20的个数
mycount = std::count (myvector.begin(), myvector.end(), 20);
//记录数组myvector中，20的个数
7.5 replace()函数
代码:
int myints[] = { 10, 20, 30, 30, 20, 10, 10, 20 };
//执行前: myvector: []
std::vector myvector (myints, myints+8);
//执行后: myvector: 10, 20, 30, 30, 20, 10, 10, 20
//执行前: myvector: 10, 20, 30, 30, 20, 10, 10, 20
std::replace (myvector.begin(), myvector.end(), 20, 99);
//执行前: myvector: 10, 99, 30, 30, 99, 10, 10, 99
7.6 fill()函数
代码:
//执行前 myvector: []
std::vector myvector (8);
//执行后 myvector: 0,0,0,0,0,0,0,0
//执行前 myvector: 0,0,0,0,0,0,0,0
std::fill (myvector.begin(),myvector.begin()+4,5);
//执行后 myvector: 5,5,5,5,0,0,0,0
//执行后 myvector: 5,5,5,5,0,0,0,0
std::fill (myvector.begin()+3,myvector.end()-2,8);
//执行后 myvector: 5,5,5,8,8,8,0,0
7.7 reverse()函数
代码:
std::vector myvector;
for (int i=1; i<10; ++i) myvector.push_back(i); // 1 2 3 4 5 6 7 8 9
//执行前: 1,2,3,4,5,6,7,8,9
std::reverse(myvector.begin(),myvector.end()); // 9 8 7 6 5 4 3 2 1
//执行后: 9,8,7,6,5,4,3,2,1
7.8 sort()函数
代码:
//升序
bool myfunction (int i,int j) { return (i myvector (myints, myints+8);
//执行后: myvector: 32,71,12,45,26,80,53,33
//缺省的排序是升序(<)
//执行前: 32,71,12,45,26,80,53,33
std::sort (myvector.begin(), myvector.begin()+4);
//执行后: 12,32,45,71,26,80,53,33
//执行前: 12,32,45,71,26,80,53,33 using function as comp
std::sort (myvector.begin()+4, myvector.end(), myfunction);
//执行后: 12,32,45,71,26,33,53,80
// using object as comp
//执行后: 12,32,45,71,26,33,53,80
std::sort (myvector.begin(), myvector.end(), myobject);
//执行后: 12,26,32,33,45,53,71,80
}
7.9 merge函数
代码:
将两个有序的组合sort1[], sort2[]。归并成一个新的有序组合。
int first[] = {5,10,15,20,25};
int second[] = {50,40,30,20,10};
std::vector v(10);
std::sort (first,first+5);
std::sort (second,second+5);
//执行前: first: 5,10,15,20,25
// second: 10,20,30,40,50
// v:[]
std::merge (first,first+5,second,second+5,v.begin());
//执行后: first: 5,10,15,20,25
// second: 10,20,30,40,50
// v:5,10,10,15,20,20,25,30,40,50
7.10 min()函数
代码:
//输出: 1
std::cout << "min(1,2)==" << std::min(1,2) << '\n'
//输出: 1
std::cout << "min(2,1)==" << std::min(2,1) << '\n';
//输出: 'a'
std::cout << "min('a','z')==" << std::min('a','z') << '\n';
//输出: 2.72
std::cout << "min(3.14,2.72)==" << std::min(3.14,2.72) << '\n';
7.11 max()函数
代码:
//输出: 2
std::cout << "max(1,2)==" << std::max(1,2) << '\n'
//输出: 2
std::cout << "max(2,1)==" << std::max(2,1) << '\n';
//输出: 'z'
std::cout << "max('a','z')==" << std::max('a','z') << '\n';
//输出: 3.14
std::cout << "max(3.14,2.72)==" << std::max(3.14,2.72) << '\n';
7.12 二分查找
代码:
lower_bound(val), 返回容器中第一个值 >= val的元素的iterator位置
upper_bound(val): 返回容器中第一个值 > val的元素的iterator位置。
7.11 堆排序
std::make_heap将[start, end)范围进行堆排序，默认使用less, 即最大元素放在第一个。
std::pop_heap将front（即第一个最大元素）移动到end的前部，同时将剩下的元素重新构造成(堆排序)一个新的heap。
std::push_heap对刚插入的（尾部）元素做堆排序。
std::sort_heap将一个堆做排序,最终成为一个有序的系列，可以看到sort_heap时，必须先是一个堆（两个特性：1、最大元素在第一个 2、添加或者删除元素以对数时间），因此必须先做一次make_heap.
代码:
//升序。左a右b，当a>b的时候，双方交换位置，
bool inc_cmp(int a,int b){ return a > b; }
//降序
bool des_cmp(int a, int b){ return a < b; }
int num[10]={3, 1, 2, 5, 6, 4};
int main()
{
//默认建立一个大根堆。
make_heap(num, num+6);
//小根堆: make_heap(num, num+6, inc_cmp);
}
vector ivec;
for(int i=3;i<=7;++i)
ivec.push_back(i);
for(int i=5;i<=9;++i)
ivec.push_back(i);
for(int i=1;i<=4;++i)
ivec.push_back(i);
//执行前: 3,4,5,6,7,5,6,7,8,9,1,2,3,4
make_heap(ivec.begin(),ivec.end());//做最大堆排序，其实还在vector容器内
//执行后: 9,8,6,7,7,5,5,3,6,4,1,2,3,4
//执行前: 9,8,6,7,7,5,5,3,6,4,1,2,3,4
pop_heap(ivec.begin(),ivec.end());//删除最大堆，其实是把数据放到最后了！
//执行后: 8,7,6,7,4,5,5,3,6,4,1,2,3,9
//执行前: 8,7,6,7,4,5,5,3,6,4,1,2,3,9
ivec.pop_back();
//执行后: 8,7,6,7,4,5,5,3,6,4,1,2,3
//执行前: 8,7,6,7,4,5,5,3,6,4,1,2,3
pop_heap(ivec.begin(),ivec.end());//删除最大堆，其实是把数据放到最后了！
//执行后: 7,7,6,6,4,5,5,3,3,4,1,2,8
//执行前: 7,7,6,6,4,5,5,3,3,4,1,2,8
ivec.pop_back();
//执行后: 7,7,6,6,4,5,5,3,3,4,1,2
//执行前: 7,7,6,6,4,5,5,3,3,4,1,2
ivec.push_back(15);
//执行后: 7,7,6,6,4,5,5,3,3,4,1,2,15
//执行前: 7,7,6,6,4,5,5,3,3,4,1,2,15
//放入最大堆，其实是把新加入的数据，按照堆排加入堆内
push_heap(ivec.begin(),ivec.end());
//执行后: 15,7,7,6,4,6,5,3,3,4,1,2,5
//执行前: 15,7,7,6,4,6,5,3,3,4,1,2,5
sort_heap(ivec.begin(),ivec.end());//把堆排顺序，还原成一般的排序算法
//执行后: 1 2 3 3 4 4 5 5 6 6 7 7 15
7.12 归并排序
void mergeSort(vector & nums, int left, int right) {
int mid = (left + right)/2;
if(left < right) {
mergeSort(nums, left, mid);
mergeSort(nums, mid+1, right);
merge(nums, left, mid, right);
}
}
void merge(vector & nums, int left, int mid, int right) {
if(left >= right){
return;
}
vector returnNums;
int i = left, j = mid+1;
for(; i<=mid && j<=right;) {
if(nums[i] < nums[j]){
returnNums.push_back(nums[i]);
i++;
}else {
returnNums.push_back(nums[j]);
j++;
}
}
while(i<=mid) {
returnNums.push_back(nums[i]);
i++;
}
while(j<=right) {
returnNums.push_back(nums[j]);
j++;
}
for(int start = 0; start < returnNums.size();start++) {
nums[start+left] = returnNums[start];
}
}
7.13 快速排序
void quickSort(vector & nums, int left, int right) {
if(left > right){
return;
}
int m = quickSort0(nums, left, right);
quickSort(nums, left, m-1);
quickSort(nums, m+1, right);
}
int quickSort0(vector & nums, int left, int right) {
cout<<"left: "<= right) {
return left;
}
int pos = left;
while(left < right) {
while(left < right && nums[right] >= nums[pos]) {
right--;
}
if(left < right) {
swap(nums[pos], nums[right]);
pos = right;
}
while(left < right && nums[left] < nums[pos]) {
left ++;
}
if(left < right) {
swap(nums[pos], nums[left]);
pos = left;
}
}
return pos;
}
